Device for preventing damage to radioactive sources in lead-filled trays or drawers



Dec. 31, 1968 P. H. BEDROSIAN 3,419,320

DEVICE FOR PREVENTING DAMAGE TO RADIOACTIVE SOURCES IN LEADFILLED TRAYS OR DRAWERS Filed Aug. 29, 1967 INVENTOR F I G 4 Paul H. Bedrosion ATTORNEY United States l atent tary of the Department of Health, Education, and Welfare Filed Aug. 29, 1967, Ser. No. 664,027 9 Claims. (Cl. 312-352) ABSTRACT OF THE DISCLOSURE The disclosure relates to a mechanical safety device having a rectangular metal frame which is hinged to a bar along one long side thereof. On the opposite side of the frame is provided a pivoted, spring-loaded cam unit which, when held in the cocked position, lies within the open space of the frame and does not protrude above the upper plane of the frame member to which it is attached. The cam is locked by a pin which fits into a notch on the side of the cam. This pin is part of a spring-loaded cover unit which is hinged, by removable pins, to the frame at its side opposite the cam. When the cover is in locked position, it lies in the horizontal plane and is fiush with the upper surface of the frame. In operation, the frame is attached by the hinged bar to a lead-filled tray or drawer in the area holding radioactive sources such as needles. When the sources lie properly within the tray or drawer, the safety device, with the cover closed against the frame, can be lowered on them and the drawer can be closed. If any of the sources protrude above the top of the drawer, the source will strike the cover from the bottom thereof causing the pin on the cover to disengage the cam which will then spring into position such that it will prevent the frame of the device from resting completely on the tray. With the frame so elevated by the sprung cam, the drawer cannot be closed thereby avoiding accidental damage to the sources.

The present invention relates to a safety device, and, more particularly, a device for preventing damage to radioactive sources in lead-filled trays or drawers.

One of the problems which has occurred in the storage of radium sources, such as radium needles, has been the accidental breakage of such needles in the conventional lead trays or drawers in which they are normally stored. For example, such needles are normally elongated and accidents have occurred in which the needles, while standing on end, were broken by being cut in the drawer upon closing thereof. The resultant contamination is dangerous and, furthermore, is of considerable nuisance.

Similar problems of an analogous nature appear wherever fragile articles are desired to be stored or maintained in a drawer, particularly where such fragile article has a dimension which exceeds the height of the drawer, and where there is relatively frequent use of the fragile articles with removal from the drawer and then subsequent replacement and closing of the drawer.

It is therefore an object of the present invention to overcome the dangers and deficiencies of the prior art, such as indicated above. It is another object of the present invention to safely store fragile articles, particularly those having at least one large dimension, in a drawer in such a manner that when the fragile article is placed in the drawer with its greater dimension projecting above the height of the drawer, it is impossible to close the drawer, therefore, breakage of the fragile article is obviated.

It is another object of the present invention to provide a safety device for insertion in a drawer which safety device will prevent closing of the drawer when an article in the drawer projects above the height thereof.

These and other objects of the nature and advantages of the instant invention Will be more apparent from the following detailed description taken in conjunction with the drawing therein:

FIG. 1 is a perspective view of one embodiment of the present invention;

FIG. 2 is a section taken along line 22 of FIG. 1;

FIG. 3 is a perspective of the embodiment of FIG. 1 shown in a different operative position; and

FIG. 4 is a side elevational view partially in section showing the cover resting on the end of the cam.

The invention essentially relates to a safety device for inhibiting the closing of a drawer or tray when articles projecting upwardly would be sheared by the closure of the drawer or tray, and includes a metal frame having a spring-loaded pivoted cam unit mounted therein locked into cocked position by a pin which is part of a springloaded cover unit which is hinged to the frame; so that when the cover is in locked position it lies in a horizontal plane flush with the upper surface of the frame so that the drawer or tray can be properly closed, however, when an article protrudes above the drawer, it will strike the bottom of the cover causing the pin to disengage the cam which will then spring into position such that it will prevent the frame of the device from resting completely within the drawer thereby preventing closing of the drawer.

The figures of the drawing show an embodiment 30 of the present invention in solid lines located within a tray or drawer 32 shown in phantom. The device 30 comprises essentially a rectangular frame 10, preferably made of metal, which is hinged to a bar 12 along its back side thereof. The bar 12, in turn, is connected to the rear portion of the drawer or tray 32 so that, in effect, the frame 10 is hingedly connected adjacent the rear of the drawer or tray 32 so that it may be rotated about the bar 12. It is understood that any suitable hinging means for connecting the frame 10 to the rear portion of the tray or drawer 32 would be suitable, and that the precise portion of the connection of such hinge to the tray or drawer 32 may be subject to various designs.

Noting FIG. 3, it may be seen that the frame 10 is essentially annular defining a storage space 34 in the interior thereof. Also, while such annular frame 10 is shown to be rectangular, it is understood that it may in general be of any shape, although it is usually most desirable that it correspond to the general interior dimensions of the tray or drawer 32 in which it is placed. It should be understood, however, that it is Within the scope of the present invention to provide a plurality of such frames within a single tray or drawer or to provide such a frame 10 within a drawer 32 wherein the frame 10 covers only a portion of the tray or drawer 32.

Along the side of the annular frame 10 opposite the bar 12 or other suitable hinge is located a cam unit 14 which preferably comprises a generally fiat or planar cam plate 36, which is shown in detail in FIG. 2. The cam unit 14 also includes a pivot 38 to which the cam plate 36 is attached to the frame 10, and a coil spring 40 which, as illustrated in FIG. 2, urges the plate 36 about the pivot 38 in a counterclockwise direction. A stop 42 is provided to limit the rotation of the cam plate 36 about the pivot 38.

Noting particularly FIG. 2, it is seen that the width of the cam plate 36 should be no greater than the height of the frame 10 so that in the position illustrated in FIG. 2 (corresponding to the closed position illustrated in FIG. 1) the cam plate 36 is maintained within the vertical dimensions of the frame 10. On the contrary, and as shown in phantom in FIG. 2, the length of the cam plate 36 should be greater than the height of the frame 10, for reasons explained below, Thus, the pivoted, spring-loaded cam plate 36 lies within the open space of the frame and does not protrude beyond the frame 10 to which it is attached when the cam unit 14 is in the cocked position as shown in FIGS. 1 and 2.

The cam plate 36 is provided with a notch 18 along one of its sides thereof so that such cam plate may interlock with a pin 16 which fits into such notch 18 as shown in FIGS. 1 and 2. The pin 16, which may be generally rectangular as shown in FIG. 3, preferably has a beveled portion 17.

The frame 10 is provided with a cover 20 which is preferably constructed to cover only the storage space 34 and, in closed position, to lie coplanar with the top surface of the frame 10. The cover is hinged, preferably by removable pins 44, to the frame 10 at its side opposite from the cam unit 14. The pin 16 extends from the cover 20, and is preferably generally coplanar therewith. When the cover 20 is in the closed and cocked position over the space 34 of the frame 10, it lies in a horizontal plane and is flush with the upper surface of the frame 10. T spring 43, associated with the cover hinge 44, is adapted to urge the cover downwardly and into intimate contact with the frame 10.

In the embodiment shown, the cam unit is located within a recess 46 along the inner periphery of the front side of the frame 10. Similarly, the cover 20 is also provided with a recess 48 into which the pin 16 projects from that portion 50 of the cover adjacent the recess 48. It is of course understood that the recesses 46 and 48 are not essential and/or that the cam unit 14 may be attached to the outer, rather than inner, periphery of the annular frame 10.

A recess may be provided in the drawer 32 to facilitate opening the device. A pair of prongs 62, connected to the underside of the frame 10, project into the recess 60 when the device is closed. A suitable instrument (not shown) such as a rod or the finger of the user may be inserted between the prongs 62 to lift up the frame 10.

In operation, the frame 10 is attached by the hinge bar 12 to a lead-filled tray or drawer in the area holding radioactive sources, such as the needles 52. As indicated above, the width and length of the device 30 should be governed by the width and length of the source area of the tray and this is often two inches by three to six inches. When the sources lie properly within the tray or drawer 32, the device 30, in cocked position shown in FIG. 1, can be rotated downwardly about the hinge 12 and lowered over such sources and the drawer can be closed. However, if any of the sources protrude above the top of the drawer 32, such as shown in FIG. 3 (note the upwardly extending needles 52), as the device 30 is rotated downwardly, the needles will contact the under surface of the cover 20. This will cause the interlocking pin 16 and notch 18 of the cam plate 36 to disengage, since such engagement is merely frictional as can be seen in FIG. 2.

As soon as the pin 16 and the cam plate 36 disengage, the spring 40, previously urging the cam plate 36 into engagement with the pin 16, will effect a further rotation of the cam plate 36 about the pivot 38 to first effect engagement of the cam plate 36 with the beveled face 17 of the pin 16 to thereby force the cover 20 upwardly against the action of the spring 44. The rotation of the cam 36 con tinues until the cam engages the stop 42 and is at or slightly past its vertical position, shown in FIG. 3 and also in FIG. 2 in phantom. At this point, depending on the design of the device 30, the ends 54 and 56 of the cam plate 36 may provide either one, or both, of two functions. Thus, the bottom end 54, by forcing against the bottom of the tray 32, will lift the frame 10 upwardly about its hinge 12. With the frame 10 so elevated by the sprung cam unit 14, the drawer 32 cannot be closed avoiding, thereby, accidental damage to the sources 52.

Coincident thereto, or as an alternative thereto, if a shorter cam plate 36 is provided or the cam plate is pivoted to the frame 10 at a higher elevation than shown in FIG. 2, the upper end 56 of the cam plate 36 will engage with the underside of the pin 16 thereby preventing the cove-r 20 from being closed upon an attempt to close the drawer 32.

After the protruding needles have been properly arranged in the drawer, the cam unit 14 may be readily cooked by turning it to its flush position and the spring (43) loaded cover 20 may then be depressed so that the pin 16 and the notch 18 of the cam plate 36 are once more in interlocking engagement. The device 30 may then be pivoted downwardly to the fully closed position shown in FIG. 1 so that the drawer may be closed.

Without the device 30, the protruding sources 52 would be sheared by the closing action of the drawer and the radium salts contained therein would be released to contaminate the area.

It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention. The device 30 may be formed of any suitable materials, such as various metals, woods or plastics. The type of inter-frictional engagement between two friction elements may be varied, as well as the structural details. Therefore, the invention is not to be considered limited to what is shown in the drawings and described in the specification.

What is claimed is:

1. A safety device for inhibiting the inadvertent shearing of frangible articles projecting upwardly from a tray or drawer, said device comprising an annular frame having an outer size and shape for fitting within the tray or drawer in which said safety device is to be used;

means for hingedly connecting said frame to the tray or drawer in which said device is to be used;

means for covering the opening within said annular frame, said covering means being hinged to said frame along that portion of said frame carrying said means for hingedly connecting said frame to the tray or drawer;

a first friction member extending outwardly from said covering means;

a cooperative friction element pivotally connected to said frame along that portion of said frame opposite that portion of said frame carrying said hinge means and frictionally engaging said first friction member when said covering means is in tight engagement over the opening of said frame, said cooperative friction element having means thereon to hold a portion of said device out of its normal horizontal plane in the drawer when said friction member and element are not engaged so that the drawer cannot be closed; and

spring means for urging said cooperative friction ele ment about its pivot so that said spring exerts a force tending first to engage said cooperative friction element with said first friction member while maintaining said holding means on said friction element in its inoperative position, and second to move said cooperative friction element beyond its engagement position with said friction member to the operative position of said holding means when the frictional contact between said friction element and friction member has been broken, whereby said holding means moves to the operative position when said covering means is displaced upwardly relatively to said frame by a projecting article in the drawer thereby preventing closure of said drawer.

2. A device in accordance with claim 1 wherein said annular frame and said covering means are of generally rectangular configuration and said covering means is generally coplanar with the top surface of said frame; said device further comprising a second spring means urging said cover downwardly; said first friction member comprising a pin lying gene-rally in the plane of said cover, said cooperative friction element comprising an elongated cam plate having its pivot at the approximate center thereof, the width of said cam plate being no greater than the thickness of said annular frame and the length of said cam plate being substantially greater than the thickness of said annular frame, said cam plate being aligned essentially perpendicularly to the plane of said cove-r and said pin, said cam plate having a pin-engaging notch along one side thereof which engages said pin thereby effecting said frictional engagement when said covering means is in tight engagement over the opening of said frame, an end of said cam plate holding a portion of said device out of its normal plane in the drawer when said pin is not engaged in said notch.

3. A device in accordance with claim 2 wherein said covering means has a recess into which said pin extends from that portion of the cover adjacent said recess.

4. A device in accordance with claim 2 wherein said pivotal connection of said cam plate to said frame is along the inner periphery of said frame.

5. A device in accordance with claim 2 wherein said frame has a recess in which lie said cam plate and said pivotal connection of said cam plate to said frame.

6. A device in accordance with claim 2 wherein said cam plate is planar.

7. A device in accordance with claim 1 wherein said hinge connection of said cover to said frame is removable.

8. A device in accordance with claim 1 wherein said means to hold a portion of said device out of its normal plane in the drawer comprises means to displace said frame at its free unhinged end away from contact with the drawer in which said device is contained.

9. A device in accordance with claim 2 wherein said end of said cam plate which comprises means to hold a portion of said device out of its normal plane in the drawer serves to engage with said pin to hold said covering means in open position above said frame.

References Cited UNITED STATES PATENTS 2,731,261 1/1956 Drum 4926 X 2,733,090 1/1956 Coplen 10963.5 2,778,326 1/1957 Guzik 10963.5 3,168,165 2/1965 Bagnasco 4927 JAMES T. MCCALL, Primary Examiner.

US. Cl. X.R. 

